Suppression of vascular endothelial growth factor expression at the transcriptional and post-transcriptional levels

Gene expression is regulated at the transcriptional and post-transcriptional levels. Therefore, in order to achieve a high level of silencing, which includes minimizing any residual expression of a target gene, suppression at both the transcriptional and post-transcriptional levels is required. In this study, we describe a new method for highly efficient gene silencing that combines zinc finger protein-mediated transcriptional repression and small interfering RNA (siRNA)-mediated inhibition of post-transcriptional events. To measure the amount of gene expression under various conditions, we used a luciferase reporter gene that was driven by a variety of promoters, including that of the human vascular endothelial growth factor-A (VEGF-A) gene. We also measured expression of the endogenous VEGF-A gene. Inhibition of gene expression by each of the two individual technologies was effective, but in-depth analyses revealed residual expression of the target gene. The combination of specific zinc finger transcription factors and siRNAs greatly enhanced the silencing of the human VEGF-A gene, not only when cells were grown in the presence of normal amounts of oxygen but also under conditions of hypoxic stimulation. These results suggest that a bi-level approach to the silencing of VEGF-A expression may be clinically beneficial as part of a cancer treatment protocol

Transcatheter arterial embolization for traumatic mesenteric bleeding: a 15-year, single-center experience

PURPOSE:We aimed to assess the safety and effectiveness of transcatheter arterial embolization (TAE) for mesenteric bleeding following trauma.METHODS:From 2001 to 2015, 12 patients were referred to our interventional unit for mesenteric bleeding following trauma, based on clinical decisions and computed tomography (CT) images. After excluding one patient with no bleeding focus and one patient who underwent emergency surgery, a total of 10 patients (male:female ratio, 9:1; mean age, 52.1 years) who underwent super selective TAE of visceral arteries were included in this study. Technical and clinical success, complications, and 30-day mortality rate were analyzed.RESULTS:In 10 patients who underwent TAE, the types of trauma were motor vehicle collision (n=6), fall (n=2), assault (n=1), and penetrating injury (n=1), and the bleeding arteries were in the pancreaticoduodenal arterial arcade (n=4), jejunal artery (n=3), colic artery (n=2), and sigmoid artery (n=1). N-butyl-2-cyanoacrylate (NBCA) (n=2), microcoils (n=2), and combinations of NBCA, microcoils, or gelatin sponge particles (n=6) were used as embolic agents. Technical success was achieved in all 10 patients, with immediate cessation of bleeding. Clinical success rate was 90% (9/10), and all patients were discharged with no further treatment required for mesenteric bleeding. However, one patient showed rebleeding 10 days later and underwent repeated TAE with successful result. There were no TAE-related ischemic complications such as bowel infarction. The 30-day mortality rate was 0%.CONCLUSION:Our clinical experience suggests that TAE used to control mesenteric bleeding following trauma is safe and effective as a minimally invasive alternative to surgery

Inadvertent discogram during transforaminal epidural injection in patients with lumbar disc herniation -A report of 2 cases-

The transforaminal epidural injection (TFEI) has been preferred in many cases because it can deliver the injected dose of medication closer to the nerve root and better facilitate ventral epidural flow compared to other methods. However, in patients with deformities not demonstrated on fluoroscopic imaging, the needle may enter unwanted locations. We treated two cases of intradiscal injection of contrast dye, during the TFEI, in patients with lumbar disc herniation

The potent protective effect of wild ginseng (Panax ginseng C.A. Meyer) against benzo[alpha]pyrene-induced toxicity through metabolic regulation of CYP1A1 and GSTs

Wild Panax ginseng C.A. Meyer (WG) is a well-known medicinal herb. In this study, the protective effects of a water extract from the root of WG on benzo[alpha]pyrene (BP)-induced hepatotoxicity and the mechanism of these effects were investigated for the first time. The effects of WG on liver toxicities induced by BP were assessed by blood biochemical and histopathological analyses. BP caused severe liver injury in rats, as indicated by elevated plasma ALT, AST and LPO levels. Pretreatment with WG for 4 weeks completely abrogated increases in the ALT, AST and LPO levels when challenged with BP. Reductions in GSH content and GST activity by BP were reversed by WG. These protective effects of WG against BP-induced toxicity were consistent with the results of histopathological examinations. We next examined the effects of WG on the gene expression of the enzymes that metabolize BP in H4IIE cells. CYP1A1 mRNA and protein expression were increased by BP. WG moderately inhibited BP-induced CYP1A1 gene expression. Moreover, GSTA2, GSTA3 and GSTM2 gene expressions were significantly increased by WG through the Nrf2/antioxidant responsive element pathway for enzyme induction. In summary, WG is efficacious in protecting against BP-induced hepatotoxicity as results of metabolic regulations through both the inhibition of metabolic enzyme activation and the enhancement of electrophilic detoxification, implying that WG should be considered a potential chemopreventive agent

Characterization of diverse natural variants of CYP102A1 found within a species of Bacillus megaterium

An extreme diversity of substrates and catalytic reactions of cytochrome P450 (P450) enzymes is considered to be the consequence of evolutionary adaptation driven by different metabolic or environmental demands. Here we report the presence of numerous natural variants of P450 BM3 (CYP102A1) within a species of Bacillus megaterium. Extensive amino acid substitutions (up to 5% of the total 1049 amino acid residues) were identified from the variants. Phylogenetic analyses suggest that this P450 gene evolve more rapidly than the rRNA gene locus. It was found that key catalytic residues in the substrate channel and active site are retained. Although there were no apparent variations in hydroxylation activity towards myristic acid (C14) and palmitic acid (C16), the hydroxylation rates of lauric acid (C12) by the variants varied in the range of >25-fold. Interestingly, catalytic activities of the variants are promiscuous towards non-natural substrates including human P450 substrates. It can be suggested that CYP102A1 variants can acquire new catalytic activities through site-specific mutations distal to the active site

Prevalence and risk factors of Helicobacter pylori infection in Korea: Nationwide multicenter study over 13 years

Background : The aim of this study was to evaluate the time trend of seropositivity of Helicobacter pylori (H. pylori) over the period of 13 years in an asymptomatic Korean population, and investigate associated risk factors. Methods : This cross-sectional nationwide multicentre study surveyed anti-H. pylori IgG antibodies in 19,272 health check-up subjects (aged [greater than and equal to]16 years) in 2011. Risk factors for H. pylori infection were investigated using logistic regression. Seropositivity in asymptomatic subjects without H. pylori eradication was compared between the years 1998 and 2005. Birth cohort effects were also evaluated. Results : After exclusion of subjects with a history of H. pylori eradication therapy (n = 3,712, 19.3%) and gastric symptoms (n = 4,764, 24.7%), the seroprevalence of H. pylori infection was 54.4% in 10,796 subjects. This was significantly lower than the seroprevalence of 59.6% in 2005 and that of 66.9% in 1998, and this decrease of seropositivity of H. pylori became widespread across all ages and in most areas of the country. This decreasing trend could be explained by cohort analysis. All younger birth cohorts had a lower seroprevalence of H. pylori than older birth cohorts at the same age. Decreased seroprevalence within the same birth cohorts also accounted for this phenomenon. Clinical risk factors of H. pylori infection were higher cholesterol level ([greater than and equal to] 240 mg/dl) (OR = 1.33; 95% CI = 1.14-1.54), male gender, older age, low income, and residence in a rural area. Conclusions : A decreasing trend of H. pylori seroprevalence due to a birth cohort effect requires further studies on its related human host factors as well as socio-economic and hygienic factors. In addition, the relationship between H. pylori infection and high cholesterol level needs more investigation regarding underlying pathogenesis.This work was supported by the National Research Foundation of Korea (NRF) grant for the Global Core Research Center (GCRC) funded by the Korea government (MSIP) (No. 2011-0030001)Peer Reviewe